Tosh Creek and the Tosh Creek Watershed are located in the Overlake neighborhood of Redmond, just west of Marymoor Park. The watershed includes the Microsoft campus. A map of the project area (outlined in pink) may be viewed here: Tosh Creek Watershed Restoration Project Area. Tosh Creek flows from Redmond's Overlake neighborhood into the Sammamish River.

What is the Tosh Creek Watershed Plan?

Completed in 2015, the Tosh Creek Watershed Restoration Plan determines the location and design of restoration work across the entire Tosh Creek Watershed. The plan identifies stormwater retrofit projects, in-stream stabilization, habitat and riparian projects, and upgrades to stormwater infrastructure. These improvements will provide stream conditions that support aquatic life and protect the residents and businesses living and working around Tosh Creek, now and in the future.

How does Tosh Creek relate to the Citywide Management Plan?

In 2013, the Redmond City Council adopted the Citywide Watershed Management Plan (WMP) which identified six priority water bodies for restoration by 2060, including Tosh Creek. The plan identifies projects and actions the City of Redmond can take to address water quality issues, primarily from stormwater impacts, needed to make Tosh Creek healthy again.

The WMP is a policy document that focuses on the restoration and protection of all of Redmond’s water bodies, including over 50 miles of our local creeks and shorelines. These water bodies include Bear Creek, Evans Creek, Lake Sammamish and the Sammamish River.

Why does Tosh Creek Watershed need restoration work?

The stormwater pipes, ponds and vaults in the Tosh Creek Watershed do not meet today’s standards. The neighborhoods and commercial areas were built without modern stormwater controls to protect Tosh Creek. At times, this has resulted in fast water flows, frequent flooding of roads and erosion. This causes steep and unstable creek banks, degraded salmon habitat, drainage issues and water damage to properties. Visit Tosh Creek Fish! to learn more about the fish found in Tosh Creek and the benefits of restoration work.

I thought Redmond already addressed this by improving the culvert under West Lake Sammamish Parkway. Why are additional projects needed?
In 2013, we took the first step of replacing the culvert at West Lake Sammamish Parkway. The old culvert flooded nearly every year due to accumulated stream sediment. The new culvert addresses the flooding problem; however, sediment continues to clog salmon spawning beds and harm aquatic species. Our next step is to stop sediment erosion by fixing the stormwater flows that cause it.

How did you decide which projects to pursue?

We considered a variety of options for restoring Tosh Creek. Feedback from Redmond residents played an important role in our decision-making by helping us understand where there are currently drainage, flooding and erosion problems.

Along with public input, we evaluated proposed options based on their feasibility, cost and the benefit they would provide to determine which projects to implement. Some of the reasons for selecting these projects include the ability to provide long-term solutions, relatively lower impact to the surrounding environment and neighborhood, technical feasibility, and efficiency in fulfilling the project purposes.

How are prioritized projects being funded?

Tosh Creek received funding from the following sources since planning and development of the plan began:

The 50th Way Flood Reduction project will be constructed in summer 2016. The 156th Flow Splitter project is fully funded, under final design, and is proposed for construction in 2017. The Tributary B Restoration Project Project is fully funded, currently evaluating alternatives and construction is proposed for 2018. The Onyx Pond and In-Stream Restoration projects have completed 30 percent design and are seeking additional funding with proposed construction in 2020. The Prescott Vault project is proposed for construction in 2022.

Construction Overview and Anticipated Impacts

What impacts will construction have on my neighborhood?

Construction impacts will vary depending on the Tosh Creek project. Construction of the 50th Way Flood Reduction project may require some temporary detours. You may also notice noise and other typical construction impacts.

The Tosh Creek project team is committed to working with nearby neighbors. Prior to construction, we will host community meetings to learn about and discuss your questions and concerns.

What are some of the impacts I can expect?

While construction can be disrupting at times, we are committed to being a good neighbor and will minimize impacts where possible and help you understand the impacts you may experience. During construction, you can expect:

Public Process

How will you communicate with me about projects near my property?

We understand that these projects may inconvenience you during construction. We are committed to listening to your concerns, working with you to minimize impacts as best we can, and keeping you informed during design and construction. We will communicate with you a few different ways:

During the design phase, we are hosting meetings and will provide information online, so that you have the opportunity to voice your comments and questions and we can discuss these with you.

Before construction, we will:

(a) Distribute surveys to nearby neighbors, so that we can gather contact information, understand your individual needs and concerns, and to help resolve issues.
(b) Host community meetings to discuss concerns and help you understand what will happen during construction.

During construction, residents will receive email updates and hand-delivered flyers when appropriate from the outreach team.

Throughout the project, you can contact us using the project email and phone number.

As needed, we will meet with individual residents to resolve concerns.

How will our input be used?

If you know of any flooding, erosion, or other drainage problems in and around Tosh Creek, please let the City know! This kind of information can influence the types and locations of future projects.

How can I help?

You can call, email, or complete a comment form on the project’s website to report your drainage concerns. We are using your input to help inform future improvements to Tosh Creek.